1. Field of the Invention
The present invention relates to a brake control apparatus for automotive vehicles for normalizing abnormal behavior of the vehicle such as spin, drift out or the like.
2. Description of the Prior Art
In a conventional brake control apparatus of this kind as disclosed in Japanese Patent Laid-open Publication No. 4-257756, a target slip ratio of road wheels is determined in accordance with movement condition of the vehicle, and an actual slip ratio of the road wheel is detected to produce a feedback control signal In accordance with a difference between the target slip ratio and the actual slip ratio. The feedback control signal is applied to a hydraulic brake control system for control of hydraulic braking fluid supplied to each slave cylinder of the road wheels. Thus, the hydraulic brake control system is controlled by the feedback control signal in such a manner that the actual slip ratio of the road wheel becomes identical with the target slip ratio.
In the conventional brake control apparatus, however, a quick control response of the hydraulic brake control system may not be effected under such a feedback control as described above, and the hydraulic brake control system may not be controlled in accordance with road surface conditions. For this reason, it is unable to quickly normalize abnormal behavior of the vehicle in a high precision.